SSL/TLS protocols use ciphers such as AES,DES, 3DES and RC4 to encrypt the content of the higher layer protocols and thus provide the confidentiality service.
Normally the output of an encryption process is a sequence of random looking bytes.

Recently a researchers has discovered that the there is a stronger bias in RC4, which make statistical analysis of cipher text more practical.

As RC4 Ciphers are found to have a variety of cryptographic weaknesses, we would stop supporting RC4 Cipher from the ClearPass version 6.6.7 and version 6.7.0.